Screw jack



F. DE BENEDETTI.

SCREW JACK.

. APPLICATION FILED NOV. 29. m9.

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Patentefl June 13, 1922.

and an FRANCESCO DE-BENEDETTI, 0F TUB/IN, ITALY.

SCREW JACK.

Application filed November 29, 1919. Serial No. 341,496.

To all 107mm. 2'25 may concern.

Be it known that I, Fnimonsoo Dn Bunnnnr'rr, a subject of the King of- Italy, and resident of Turin, l'taly, have invented certain new and useful Improvements in Screw Jacks, of which the following is a specification.

'This invention relates to screw jacks and has for its object a screw ack in which the head or lifting member is mounted at the end of a screwthreaded spindleengaged with a nut forming part of a bevel gear, a pinion, rigid with an operating rod being removablymounted in the jacksupportor stand to mesh with said gear so that the jack is operated by rotating said rod around its axis.

This invention also comprises a folding construction of the operating rod for the purpose of reducing the space occupied by the jack when out of use, whilst imparting to said rod the required length for an easy operation.

The annexed drawing shows by way of example an embodiment of this invention, Figure 1 being a side view of the jack in operative condition; Figure 2 is a fragmentary sectional view of the top portion of the ack stand; Figure 3 is a view of the end of the operating rod with its pinion in cross section; Figure 4- is a side view of said folding rod in operative condition and Figure 5 is a view of said rod when folded, with some parts in section.

As shown by Figures l3, the jack comprises a stand 1 having a vertical recess in which is mounted to move a screwthreaded spindle 2 having a head 3. On the top of stand 1 is rotatably mounted a bevel gear 5 formed integral with a disk 4 having a central screwthreaded hole in which is engaged the screwthreaded spindle 2.

Near its top the stand 1 comprises a side extension or sleeve 6 provicing a seat in which may be journalled the end of a rod '7 having a pinion 8 adapted to mesh with the gear 5 when said rod is properly arranged in said sleeve.

Pinion 8 is secured to rod 7 at such a place as to provide on a free end portion 7' adapted to enter sleeve 6 and near the said rod end of said extension 7 is provided in the rod a groove 9 (Figure 3) adapted to be engaged by a pin 10 carried by a spring plate 11 secured on extension 6 of stand 1 (Figure 2) and projecting into the same through a hole in said sleeve 6.

Rod 7'is provided at its free end with a handle 12 by means ofw'hich'it may beeasily rotated around its axis.

The operation is as follows: Extension 7 of rod 7 is inserted into the sleeve 6 and is engaged therein by thepin or-finger 10 entering groove 9, said finger having been drawn out against the action ofspring plate 11 to enable the insertion of said rod extension. The pinion S-is'thereby brought-into engagement with; gear 5 so that by operating said rod 7 by means of handle 12 the disk 4 is rotated and the screw thread provided therein causes spindle 2 and head 3 to rise or descend according to the direction 1n which said rod is operated, said spindle and head being prevented from rotating by the engagement of the latter with the load or by any other proper means as may be desired,

When the jack is out of use the rod 7 may be removed therefrom by withdrawing finger 10 in which event said jack will occupy a reduced space; on the other hand when the jack is to be operated said rod is held in proper position by the extension 7 entering sleeve 6 and by finger 1O engaging the groove in the extension.

For the purpose of making easy the operation of the jack said rod 7 must have a certain length (about two feet), and therefore it is conveniently made up of two sections 7 and 7 the first of which is provided at one end with pinion 8 and the other one with handle 12. Said sections have their adjacent ends fork-shaped and in these fork ends is pivoted a link 13. On one of said sections is also secured a collar 15 and on the other one is mounted a freely slidable sleeve 14:.

By this arrangement when said sleeve 14 embraces the fork ends of both sections 77 these sections are held rigidly together so as to form a stiff rod (see Figure 4 whilst when sleeve 14 is moved away from collar 15 said sections are free to be folded adjacent to each other as shown by Figure 5 so that the length of the ack operating rod is reduced to a half when the same is out of use.

Sleeve 14 and collar 15 form a simple and efficient arrangement for holding rigid the rod sections 7-7 because said sleeve 14, being mounted to move freely along said rod, assumes by its own weight the locking position when the rod is arranged with pincan ion down as required for the jack operation and as shown by Figure l, and is removed from said locking position when the rod is lifted.

What I claim as my invention and desire to secure by United States Letters Patent 1s:-

1. A screw jack comprising a stand, a gear rotatably mounted on its top and having its hub formed with a threaded axial opening, a threaded lifting spindle engaged in said opening; a seat in said stand for rotatably mounting the end of a bar, an actuating bar adapted to be removably engaged in axial direction in said support and a pinion rigid on said bar and adapted to mesh with said gear when said bar is located in its seat.

2. A screw jack comprising a stand, a gear rotatably mounted thereon and having its hub formed with a threaded axial opening; a threaded lifting spindle engaged in said opening; a seat in said stand for rotatably mounting the end of a bar, an actuating bar ,sea

s 3rin lockin aro'ection in said seat ada tb a l ed to engage said groove of the actuating bar.

3. A screw jack comprising a stand having a seat formed therein; a gear rotatably mounted on said stand and having its hub formed with a threaded, axial opening; a threaded lifting spindle engaged in said opening; a pinion meshing with said gear; a bar rigid with said pinion and having an extension which projects beyond said pinion and fits removably in said seat, said extension being formed with a circumferential groove; and a spring-mounted locking projection in said seat engageable in said groove.

Signed at Turin Italy, this 6th day of November, A. D. 1919.

FRANCESCO DE BENEDETTI. 

